title: Low seroprevalence of Murray Valley encephalitis and Kunjin viruses in an opportunistic serosurvey, Victoria 2011.
abstract: OBJECTIVE
  To assess evidence of recent and past exposure to Murray Valley encephalitis virus (MVEV) and West Nile clade Kunjin virus (KUNV) in residents of the Murray Valley, Victoria, during a period of demonstrated activity of both viruses in early 2011.
  
  
  METHODS
  A cross-sectional serosurvey using two convenience samples: stored serum specimens from a diagnostic laboratory in Mildura and blood donors from the Murray Valley region. Specimens were collected between April and July 2011. The main outcome measure was total antibody (IgM and IgG) reactivity against MVEV and KUNV measured using an enzyme immunoassay and defined as inhibiting binding of monoclonal antibodies by >50%, when compared to negative controls. Evidence of recent exposure was measured by the presence of MVEV and KUNV IgM detected by immunofluorescence.
  
  
  RESULTS
  Of 1,115 specimens, 24 (2.2%, 95% CI 1.3-3.0%) were positive for MVEV total antibody, and all were negative for MVEV IgM. Of 1,116 specimens, 34 (3.1%, 95% CI 2.0-4.0%) were positive for KUNV total antibody, and 3 (0.27%) were KUNV IgM positive. Total antibody seroprevalence for both viruses was higher in residents born before 1974.
  
  
  CONCLUSIONS
  Despite widespread MVEV and KUNV activity in early 2011, this study found that seroprevalence of antibodies to both viruses was low (<5%) and little evidence of recent exposure.
  
  
  CONCLUSIONS
  Our findings suggest both viruses remain epizootic in the region and local residents remain potentially susceptible to future outbreaks.
authors.affiliation: Victorian Department of Health Centre for Immunology, Burnet Institute, Victoria Research and Development, Australian Red Cross Blood Service, Queensland Victorian Infectious Diseases Reference Laboratory Victorian Department of Health Victorian Infectious Diseases Reference Laboratory Barratt and Smith Pathology, Victoria Victorian Department of Environment and Primary Industries Victorian Infectious Diseases Reference Laboratory Victorian Department of Health Faculty of Health Sciences Office, Curtin University, Western Australia.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Williams
authors.forename: Jack S
authors.initials: JS
authors.lastname: Richards
authors.forename: Helen M
authors.initials: HM
authors.lastname: Faddy
authors.forename: Jennie
authors.initials: J
authors.lastname: Leydon
authors.forename: Rodney
authors.initials: R
authors.lastname: Moran
authors.forename: Suellen
authors.initials: S
authors.lastname: Nicholson
authors.forename: Faye
authors.initials: F
authors.lastname: Perry
authors.forename: Roger
authors.initials: R
authors.lastname: Paskin
authors.forename: Mike
authors.initials: M
authors.lastname: Catton
authors.forename: Rosemary
authors.initials: R
authors.lastname: Lester
authors.forename: John S
authors.initials: JS
authors.lastname: MacKenzie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D018068:Encephalitis Virus, Murray Valley / Q000302:isolation & purification*; D004671:Encephalitis, Arbovirus / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D066298:In Vitro Techniques; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D014739:Victoria / Q000453:epidemiology; D014901:West Nile Fever / Q000097:blood / Q000453:epidemiology* / Q000821:virology; D014902:West Nile virus / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: Kunjin; Murray Valley Encephalitis; blood donor; flavivirus; mosquito; seroprevalence